Canon CANOSCAN D660U Service Manual page 27

1) Home position test
Checks if the scanning unit operates normally. When the scanner is powered ON, the
scanning unit automatically moves to the home position. This is also a scan start position.
q Home Position
w White Calibration Plate
2) Light intensity test
Checks if the light intensity of the scanning lamp reaches the standard value. When the
scanning lamp lights, the control program reads the light reflected from the white calibration
plate with the CCD, and checks if the light intensity into each CCD of red, green, and blue
reaches the standard value. If the light intensity is below the standard value, the control
program continues the test for up to 30 seconds. If it still does not reach the standard value,
the control program returns "FALSE".
COPYRIGHT © 2000 CANON INC.
Figure 2-6
CANOSCAN D660U REV.0 JULY 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
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